1. Field of the Invention
The present invention relates in general to secondary cells and, more particularly, to an electrolytic cell and electrolytic process associated therewith, wherein dendrite growth during electrodeposition is substantially suppressed to, in turn, substantially increase the cycle life of the cell.
2. Background Art
Rechargeable, or secondary electrolytic cells, have been known in the art for many, many years. Furthermore, secondary cells constructed with lithium anodes have likewise been known in the art. Although such lithium rechargeable batteries have proven to be functional, they have been undesirable for use from a practical standpoint. Indeed, it is well known that the cycle life of such rechargeable lithium batteries are cut relatively short (compared to other types of secondary cells such as nickel-cadmium) due to the formation of dendritic growth on the working electrode during electrodeposition--wherein such dendrites typically facilitate the loss of electrochemical activity within the cell and/or internal shorting therewithin.
In an attempt to suppress such dendritic growth, various approaches have been pursued, including the utilization of an ionically conductive organic film which is deposited on the anode through a plasma polymerization process. Although such organic films have indeed exhibited ionic conductivity, they have not exhibited any detectable electronic conductivity--toward substantial uniform attraction and deposition of, for example, lithium metal ions back on the anode during electrodeposition.
Accordingly, while the prior art attempts to develop an organic surface layer which (when applied to the working electrode, and, more particularly, a lithium anode, of an electrolytic cell) will suppress dendrite growth on the working electrode during electrodeposition, the results have been less than satisfactory. Indeed, although such prior art organic films have represented a step in the right direction, none of such prior art, alone, or in combination with each other, teach, much less suggest, the utilization of a surface layer which is both ionically conductive and electronically conductive--wherein such electronic conductivity facilitates a substantially uniform attraction of the particular alkali metal ions (such as lithium ions) of the working electrode (such as a lithium anode) back through the surface layer and onto the anode during electrodeposition toward substantial suppression of dendrite growth on the anode. In addition, none of such prior art references teach, much less suggest such a surface layer which further exhibits substantial chemical equilibrium between the surface layer and the particular alkali metal electrode toward still further suppression of dendrite growth to, in turn, greatly increase the cycle life of the secondary electrolytic cell.